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Page 67
Journal of Organic & Inorganic Chemistry
ISSN 2472-1123
2
n d
E d i t i o n o f E u r o S c i C o n C o n f e r e n c e o n
Chemistry
F e b r u a r y 1 9 - 2 0 , 2 0 1 9
P r a g u e , C z e c h R e p u b l i c
Chemistry 2019
T
racer-scale chemistry has some distinguishing characteristics which makes it differ from common (macro) chemistry. For
example, the common redox and self-redox reactions 2Pu(IV)+U(IV)―>2Pu(III)+U(VI) and 2U(V)―>U(VI)+U(IV) that do not
occur in extremely diluted solutions as collisions between micro components are practically excluded. Considerable differences
in the chemical behaviour micro- and macro quantities of some actinides in the gaseous phase had also been observed. The
initial sample contains a tracer quantity of the actinide under study that was adsorbed on the surface of quartz powder. The
experiments were carried out using open quartz thermochromatographic (TC) columns (id=3 mm); oxygen served as a reagent
and helium was a carrier gas; the flow rate of the gas mixture was 20 cm
3
min
–1
; the initial sample was heated in a gas stream at
700-750 ˚C and the final temperature was –165 ˚C; the temperature gradient was –18 ˚C cm
-1
; the duration of each experiment
was 30 min. It was found that uranium formed volatile dioxide and trioxide that were adsorbed at 450±25 ˚C and 250±25 ˚C. The
values of adsorption enthalpy -ΔHao for UO
2
and UO
3
on quartz were 172±6 and 126±6 kJ mol
-1
respectively. Two plutonium
radioisotopes
238,239
Pu were used in similar experiments. Contrary to the previous results, plutonium formed three oxides. The
centres of their deposition zones were registered at 450±30˚C (PuO2), 250±30 ˚C (P
u
O
3
) and at negative temperature –105±25
˚C (PuO
4
). The values of -ΔHao for these oxides were 175±7, 122±7 and 47±6 kJ mol
-1
respectively. Results of the TC isolation
of neptunium, americium and curium oxides are also presented. In particularly, Cm formed also three oxides: CmO
2
, CmO
3
and
CmO
4
.
domanov@jinr.ruChemistry of volatile oxygen-bearing compounds
formed by U, Np, Pu, Am and Cm
Vladimir Panteleimonovich Domanov
Joint Institute for Nuclear Research, Russia
J Org Inorg Chem 2019, Volume: 5
DOI: 10.21767/2472-1123-C1-021